AMQPPoster

A library for building communication between microservices. It has simple and small API. It works with amqplib and oriented to RabbitMQ.

Installation

npm install amqp-poster

API

Instance

const Poster = require('amqp-poster');

(async () => {
	const poster = new Poster(options);
	
	await poster.init();
})();

options

{
	name: 'TestService',
	uid:  'inst1',
	subscribe: [{
		exchange:       '',
		oncePerService: true
	}],
	prefetch: 10,
	server: {
		port:     5672,
		hostname: 'localhost',
		username: 'guest',
		password: 'guest'
	}
}

key	required	type	description
name	true	string	Service name. Also it is queue name for listening
uid		string	String to identify owned queues
subscribe		array	Collection of exchanges to subscribe
subscribe[].exchange	true	string	Name of exchange to subscribe
subscribe[].oncePerService		boolean	Apply round robin to messages for one service by name (default false)
prefetch		integer	How many messages process at one time (default 1)
server	true	string	Connection url like 'amqp://guest:guest@localhost:5672'
server	true	object	Object of connection config. May have next keys: protocol, hotname, port, username, password, locale, frameMax, heartbeat, vhost

Send messages

try {
	let resp = await poster.send('ServiceName', reqObj)
	// some logic
} catch (err) {
	// Handle error
}

reqObj - object or other variable to send

respObj - response object

err - error from respond-side

Message Handler for incoming messages

poster.setMessageHandler(async (reqObj) => {
	// some logic
	
	// throw new Error('Some error');
	// or
	
	return respObj;
});

reqObj - object or other variable was sent

respObj - object or other variable to send as answer. Can be Promised value

Publish broadcast message

await poster.publish('ExchangeName', reqObj);

Handle broadcast messages

poster.setBroadcastHandler(function (reqObj) {
	// some logic
});